resolveDefaultWorkspace

Default out-of-the-box workspace location for KSL apps.

Preference order:

1. <userHome>/Documents/KSLWork — when Documents exists. Standard on macOS and Windows; also present on most desktop Linux distributions.

2. <userHome>/KSLWork — fallback for systems without a Documents folder.

Either path is created on demand by activeWorkspace when it is selected. The "KSLWork" subdirectory keeps the app's configs/ and output/ folders contained, so KSL does not pollute a user's general-purpose Documents tree.